Setting up my solar system

[Hclarkx]

Originally Posted by GravelRider

I was last there (Yellowstone only, not GTNP) 7 years ago by myself on a motorcycle, stealth camping the whole way. This will be a new experience bringing the family along.

It looks like average temps in early to mid-October will be pretty chilly. I'm just hoping we don't get any extreme lows, as I am worried about pipes freezing.

Does your RV have a bottom cover of some kind? Mine has a corrugated fiberglass/plastic or something like that. The underside is fairly well sealed. Has a few 3" louvered vents. That goes a long way between the ground underneath usually being not frozen and some heat from the not-well-insulated floor making it down there. I have tank heaters but have never used them. The water from the fresh tank never felt problematically cool even when we've see high 20's. Though several nights in the 20's along with cool days might be a different story since the sun doesn't get under there. The skirting you mentioned alone will go a long way if the ground is not yet frozen.

My batteries are in a front compartment that abuts my "basement" which never gets very cold because the propane space heater is more-or-less in that space.

[Hclarkx]

Originally Posted by hobienick

Out of curiosity, on all of the Excel curves graphs posted I see single points for each day of the year. Where does that daily point value come from? Is it an average value over several years? Is it the most recent single point value collected?

I ask because the graphs looks noisy. This is expected for a small data set for each day. If the data is just one point per day, say from the last year, then the curves need to be smoothed for more usable information. As stated several times in the thread, clouds and other events can have a significant effect on available solar power for a day.

I have learned over the years to not trust graphs when I do not have information on how the data was used to create them. The annual curves should show less noise if a sufficient sample size was used for each data point.

My plots come from hourly data generated by the NREL (National Renewable Energy Laboratory in Denver). I use their PVWatts on-line app to dig data out of their solar energy data (which is extensive and goes back more than 50 years). PVWatts will interpolate between locations if the database does not have nearby solar data. You can select by double-clicking on a location on a map. PVWatts takes into account a lot of variables such as wind and air temperature (affects panel efficiency), beam and diffuse solar radiation.

The hourly data is "representative" based on statistical analysis of historical data collected from weather stations and existing solar arrays and similar. I.e., it's what's called "statistically representative." This means it includes typical hour to hour and day to day extremes and all in between.

PVWatts models the panel type, array size, array angle and direction, any adjustments in angle or direction, losses, controller efficiency, ratio of array size to controller output rating (think clipping on the better sun days), and probably others. PVWatts was updated for the fifth time in 20 years a few years ago and has been bench marked against many actual installations.

The data is hourly as downloaded. When I plot daily values, those are the sum of the hourly solar production from the statistically representative days. You can even see intramonth seasonal changes.

Having representative daily totals allows one to plan battery and solar capacity based on when and where one camps. I.e., a system that will ride though most inclement weather. Battery size vs solar trade-offs can be examined. I.e., planning a system that minimizes generator use, or at least limits the run events.

Here's the data I use in PVWatts. I have developed a public domain spreadsheet that uses PVWatts results to examine battery and solar options. Let me know in a PM if you'd like to play with it.

[chriscowles]

Originally Posted by GravelRider

They were $500 cash for both 400 watt panels.

800W for $500 total? From where?

[chriscowles]

Originally Posted by chriscowles

800W for $500 total? From where?

Never mind. Found it: https://www.forestriverforums.com/fo...ml#post2389610

[chriscowles]

Originally Posted by GravelRider

I got more work done last night on my solar project. Dicor is now on both panels at the mounts.

GravelRider, now that they're installed, what's the measured distance between them? How comfortable are you walking between them, with regards to having enough space to keep your balance?

I have an opportunity to buy similar panels, about 39" x 65" - 72", depending on the wattage (320W-380W at $210-$265 each). Your roof looks navigable to me. Mine would be the same.

I bought rk06382's EPEver Triron 4210N SCC that was gathering dust in his garage. (Thanks, Robert.) Considering its 100V and 40A limits, I don't think I'd want to exceed 2 x 320W from the range available to me. I don't have details on the specs, yet, except that they have 3 diodes per panel.

[Hclarkx]

Originally Posted by chriscowles

GravelRider, now that they're installed, what's the measured distance between them? How comfortable are you walking between them, with regards to having enough space to keep your balance?

I have an opportunity to buy similar panels, about 39" x 65" - 72", depending on the wattage (320W-380W at $210-$265 each). Your roof looks navigable to me. Mine would be the same.

I bought rk06382's EPEver Triron 4210N SCC that was gathering dust in his garage. (Thanks, Robert.) Considering its 100V and 40A limits, I don't think I'd want to exceed 2 x 320W from the range available to me. I don't have details on the specs, yet, except that they have 3 diodes per panel.

Hiking poles!! On the glass panels. You don't need to put much weight on them to maintain balance. The glass panels are surprisingly strong.

[GravelRider]

Originally Posted by chriscowles

800W for $500 total? From where?

Originally Posted by chriscowles

Never mind. Found it: https://www.forestriverforums.com/fo...ml#post2389610

Yep! That's it. In case anyone is local and is interested, the place is called Sun Pulse Solar. Greats guys to deal with.

[GravelRider]

Originally Posted by chriscowles

GravelRider, now that they're installed, what's the measured distance between them? How comfortable are you walking between them, with regards to having enough space to keep your balance?

I have an opportunity to buy similar panels, about 39" x 65" - 72", depending on the wattage (320W-380W at $210-$265 each). Your roof looks navigable to me. Mine would be the same.

I bought rk06382's EPEver Triron 4210N SCC that was gathering dust in his garage. (Thanks, Robert.) Considering its 100V and 40A limits, I don't think I'd want to exceed 2 x 320W from the range available to me. I don't have details on the specs, yet, except that they have 3 diodes per panel.

I believe they are spaced 16" apart. I can't recall at the moment, but definitely not far off of that. I have no issues walking between them, though an extra 6" or so of space would be appreciated, but I'm plenty happy with how they are mounted. And these panels are the same width as the ones you're looking at.

Let us know if you end up buying the panels.

[Hclarkx]

Originally Posted by Hclarkx

Hiking poles!! On the glass panels. You don't need to put much weight on them to maintain balance. The glass panels are surprisingly strong.

Make that rubber tipped hiking poles!!!!!!

[drburns]

Late to this thread, but here are details on a 600 watt system I did.

One correction. The panels are in 3 pairs of 2 panels...not 2 pairs of 3 panels.

I also installed an auto transfer switch that is not shown.

https://diysolarforum.com/threads/rv...atteries.6773/

[chriscowles]

Originally Posted by drburns

Late to this thread, but here are details on a 600 watt system I did.

One correction. The panels are in 3 pairs of 2 panels...not 2 pairs of 3 panels.

I also installed an auto transfer switch that is not shown.

https://diysolarforum.com/threads/rv...atteries.6773/

What was the cost of your DIY battery? Did you already have the equipment required to build it? Previous experience?

[drburns]

It was my first experience with battery building. Learned how to build it and where to buy the parts on the same site where I shared my install.

Battery parts cost was around $1,000.

I hope this helps...

[GravelRider]

Originally Posted by drburns

It was my first experience with battery building. Learned how to build it and where to buy the parts on the same site where I shared my install.

Battery parts cost was around $1,000.

I hope this helps...

I'm quite interested in your batteries as well. When you say you have two 280 Ah batteries for $1000, is that two 12 V (4 cell) batteries for a total battery bank of 560 Ah? Or did you put together two cells in each battery and then connect two 6 V batteries in parallel for a total battery bank of 280 Ah?

[drburns]

Great question. I built two 12V batteries using four 280 Ah cells connected together. Each 4 cells has it's own BMS so that they act as two 12 volt batteries.

I then connected the two 12 volt batteries in parallel for a total capacity of 12 volts at 560 Ah.

Process was not complex...hardest part was waiting the +30 days for the parts to arrive from China. :-)

[GravelRider]

Originally Posted by drburns

Great question. I built two 12V batteries using four 280 Ah cells connected together. Each 4 cells has it's own BMS so that they act as two 12 volt batteries.

I then connected the two 12 volt batteries in parallel for a total capacity of 12 volts at 560 Ah.

Process was not complex...hardest part was waiting the +30 days for the parts to arrive from China. :-)

Holy crap! That's a great price! Do you have links to where to bought your battery cells? I may go lithium at those prices!

And what a huge battery bank!

[Boondock Saint]

"I built two 12V batteries using four 280 Ah cells"

Hi David, would you please provide me with the link and info to your batteries? I've been looking at a similar setup using 16 cells = 400ah.

THX!


.

[RedSteelManUSA]

These are my batteries (300AH RV Boat Lithium Ion Bluetooth Battery | LiFeBlue Battery), but they offer other sizes as well. I'm very happy with the batteries and the purchase process. Let me know if you need anything else.

[GravelRider]

I finally got the other two GC2 batteries mounted last night, so now I have a 430 Ah (215 usable) battery bank to pair with the 800 watt solar setup.

I'll be leaving in just over a week on a 3 week trip to Yellowstone, where I'll be boondocking/dry camping most of the time. I'm expecting temps below freezing, so I'm installing 12 V tank heating pads on all the holding tanks and some 12 V heat tape on all the exposed water lines. So, between my power hungry 12 V fridge, the heater, and the new heating elements, we'll see how the batteries and solar keep up.

There wasn't enough room to fit the four batteries longwise in a row, so I fabbed up and welded some mounts to the outside of the tongue.

[GravelRider]

We're a week into our three week trip, and everything is working flawlessly. So far the lowest our battery has gotten down to is 81%. It's been back to 100% by noonish each day.

I've had to use the generator each day to use the microwave, my wife's blow-dryer, and our electric frying pan. If it weren't for these, I'd have no use for it. Looks like the next step is to install an inverter with automatic transfer switch.

[drburns]

Sorry for my delay in replying.

Here is a link to lots of details around the Lithium batteries I use.

https://diysolarforum.com/threads/xu...e-review.3850/

Due to COVID, I have not been camping as much as usual, but I was able to do a 4 day off the grid trip two weeks ago. I ran my outside mini-fridge during the day, made multiple cups of coffee each day with my 800W K-Cup single cup machine, used the microwave a few times, charged our iPhones, and iPads, ran the lights, and used the Furnace some each day. After 4 days I still had 50% of my battery pack available. :-)

Let me know if you have any questions.